The overall objective of our investigation is to elucidate in molecular terms the mechanism by which interferon acts to affect a wide variety of fundamental viral and cellular processes. We are utilizing reovirus and simian virus 40, together with various mammalian cells in culture, to study in detail the means by which interferon treatment affects the ability of mammalian cells to catalyze viral as well as cellular coded polypeptide synthesis. BIBLIOGRAPHIC REFERENCES: Levin, K.H., and Samuel, C.E. Biosynthesis of Reovirus-specified Polypeptides. Effect of Methylation on the Efficiency of Reovirus Genome Expression in vitro. Virology (March, 1977, in press). Samuel, C.E., and Farris, D.A. Mechanism of Interferon Action. Species Specificity of Interferon and the Interferon-mediated Inhibitor of Translation from Mouse, Monkey, and Human Cells. Virology (April, 1977, in press).